Weird foam in rear underbody. How to access?

strictly

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Has any one taken a look at the foam in the rear chassis box sections of a GT?

See picture.

If you pull out the square rubber bung next to it, you can feel it Is a large foam thing.

I reckon it must be a water trap. My questions are.

1) should the bit cicled in red have a rubber bung to keep from water getting to the foam? I could not figure out from part diagrams

2) has anyone taken the bit below the rear seats out? I've seen the write up procedure removing the rear seats this is fantastic. I am wondering if below the rear seats there Is a foam bit and this is what is showing. If so that we can get to. If not then it's probably an impossible bit of wet foam to get to.

If no one knows i will remove rear seats and take a look underneath
 

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Zep

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I'm struggling to work out where you mean - is it ahead of the rear axle next to the central tunnel heat shield?
 

strictly

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Hi zep, i should have said, yes in front of rear axle, you can see the foam poking through. See picture. Under the square rubber bung you can feel the foam. I will see if I can find it in the parts diagrams.
 

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strictly

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I can't find it in the parts diagrams, see additional pics, the rear frame bit where the weird foam is i think is under the rear seats. I'm hoping that under rear seats there Is a big bit of removal foam, as from what I can see water can enter this area from underneath and rust it out.

If no one knows I will do a deep dive.

In our rusty front subframe thread there were recent pictures of rusty other brand cars due to body foam....and that got me thinking....
 

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conaero

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I was undersealing a car today and know what you mean. It’s like a black expanding foam and the excess hangs out the rear floor box section.

I’ve not explored up inside but if it’s any consolation I never see rust in this area.
 

strictly

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I was undersealing a car today and know what you mean. It’s like a black expanding foam and the excess hangs out the rear floor box section.

I’ve not explored up inside but if it’s any consolation I never see rust in this area.
That's it! Well that's at least great news. Your rusty subframe thread has been a really informative read. As your day in day out, if you ever get a chance to list some of the body places you see rust forming i would be interested!

My GT is a long term keeper, so I'm very much focused on preventative so I never have to weld it up! OK that could be wishfull thinking!
 

philw696

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I think if you keep up the preventative maintenance of keeping the underside as clean as you can and keeping it treated along with a dry garage with good ventilation you should never need to worry about rust that would lead to needing new metal welding in.
 

conaero

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That's it! Well that's at least great news. Your rusty subframe thread has been a really informative read. As your day in day out, if you ever get a chance to list some of the body places you see rust forming i would be interested!

My GT is a long term keeper, so I'm very much focused on preventative so I never have to weld it up! OK that could be wishfull thinking!
Very little tbh. Front and rear subframes obviously and the front headlight supports disintegrate but are £100 a side and bolt off, bolt on.

Rear of the sills where it meets the floor can be a bit ‘brown’ and around the drainage holes that have those paper stickers on oh and the chassis plates which I’m sure you know about.

Springs snap at the first coil up from the bottom and the anti roll bars always are heavily crusty but just corse sandpaper, treat and primer sorts those.
 

strictly

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Very little tbh. Front and rear subframes obviously and the front headlight supports disintegrate but are £100 a side and bolt off, bolt on.

Rear of the sills where it meets the floor can be a bit ‘brown’ and around the drainage holes that have those paper stickers on oh and the chassis plates which I’m sure you know about.

Springs snap at the first coil up from the bottom and the anti roll bars always are heavily crusty but just corse sandpaper, treat and primer sorts those.
Conaero, that's really awesome knowledge, thank you for taking the time.

I'll have a good look at those spots.
 

strictly

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I think if you keep up the preventative maintenance of keeping the underside as clean as you can and keeping it treated along with a dry garage with good ventilation you should never need to worry about rust that would lead to needing new metal welding in.
That is what I'm hoping for. The only thing I will add is finding and then keeping an eye on what ever the inherent water or mud traps are. I found this one the other day. See picture for location.

It might however just be a specific scenario, I washed the car then moved it to dry it, where the floor is quite sloped (75mm per 2m).

For a car that is regularly driven i can't see it as a problem.
 

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philw696

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Do you have a compressor and airline with a blow gun ?
The Detailer we had at Maserati when I was there spent time blowing every bit of water out of orifices when he was cleaning the cars.
 

strictly

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Do you have a compressor and airline with a blow gun ?
The Detailer we had at Maserati when I was there spent time blowing every bit of water out of orifices when he was cleaning the cars.
It's a good idea, I will start doing this (with waterproofs). I have been using a detailers jet dryer, but only for panel shuts rather than nooks and crannies
 

Scaf

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That is what I'm hoping for. The only thing I will add is finding and then keeping an eye on what ever the inherent water or mud traps are. I found this one the other day. See picture for location.

It might however just be a specific scenario, I washed the car then moved it to dry it, where the floor is quite sloped (75mm per 2m).

For a car that is regularly driven i can't see it as a problem.
I was due to replace the chasis plates on the Strad (handed new ones over when I sold it) but intended to drill a hole in the dimple to try and drain the water that sits on the top, ridiculous design.
 

conaero

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A note on chassis plates. Tried to order some from Scuds the other day, no stock at factory. Luckily Eurospares had stock.

The next item to disappear?
 

CatmanV2

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A note on chassis plates. Tried to order some from Scuds the other day, no stock at factory. Luckily Eurospares had stock.

The next item to disappear?

Are they actually necessary? I'm thinking of the cheese ones?

C
 

strictly

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229
A note on chassis plates. Tried to order some from Scuds the other day, no stock at factory. Luckily Eurospares had stock.

The next item to disappear?
Good to know they are cheap as chips i better order some while still available.

I think I will drill some drain holes in the new ones.

To answer catman...i don't think they do much besides being an extra bit of protection when someone puts a floor jack in the wrong place
 

strictly

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I just thought I would wrap up the thread for the time being. I have had my bottom rear seats up, but at first glance I cannot see an obvious way to connect to the weird foam i showed in the picture which is in the vicinity, so i am going to forget about it for now.

On the brightside I did buy 2 x chassis plates from eurospares which were thankfully still in stock and when I fit them I will drill a drain hole or two in them.
 

Scaf

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7,148
Keep hold of one, I’ll make a hammer form for them. Aluminium chassis plates would probably be a good idea.
I think they are essentially flat sheet steel and the pressings (that collect the water) are to add strength.

Reproducing in aluminium a great idea.